264 



leftward shift of the dorsal sl-insertion, and that of the ventral sl-insertion in Polyphaga, 

 might be correlated with a parallel shift of the hla-base from the left ventral wall (fig. 65) 

 to the left edge of the left complex (fig. 117, 177). Lamproblatta has a lateral muscle (s5b) 

 showing the s5-insertions of the basic aiTangement. Whether another muscle having a 

 much more median position (s5a) is a true part of s5 or a new muscle is unclear. In Po- 

 lyphaga s5 is completely missing - possibly in consequence of the leftward shift of si. 

 On the right side, the s4 of Polyphaga and Lamproblatta conform with the basic 

 arrangement and are easily identified. To the right of s4 both species have another muscle 

 (named s6) running to the anterior margin of R3, which might be s2 or s6. Its ventral 

 insertion is lateral (not posterior) to s4 (fig. 113, 173) and extends far laterad. This suggests 

 it to be s6. Its dorsal insertion on the right anterior margin of R3 only, not on the genital 

 pouch, however, might suggest it to be s2. But since the dorsal insertion of s6 of Anaplecta 

 and Eurycotis has expanded to the anterior margin of R3, and since s2 is small in Eurycotis 

 and very small in Anaplecta, these muscles of Lamproblatta and Polyphaga are interpreted 

 as s6; s2 is assumed to have been lost. The restriction of the dorsal s6-insertion to the 

 anterior margin of R3 (no longer in the wall of the genital pouch) would be a derived 

 feature of Polyphaga and Lamproblatta. (If the muscle should be s2, the laterad expansion 

 of its ventral insertion would be a derived feature). 



Of the secondary muscles sl2 is present (fig. 133, 188): The dorsal and ventral insertions 

 are exactly the same in both species, and, in addition, the dorsal insertion is surrounded 

 in the same way by s3, 15, and 16a. sl2 is peculiar to Lamproblatta and Polyphaga (and 

 Ergaula) and is assumedly a synapomoiphy of these species. s8 is present in Polyphaga 

 (and Ergaula) but missing in Lamproblatta. 



Cryptocercus 



The left side (fig. 147, 149, 333f) has only one muscle sl+3, with its ventral insertion 

 along the median (not the lateral) anterior margin of the subgenital plate and its dorsal 

 insertion only on and near the basal Une (not in the more posterior walls of the genital 

 pouch, fig. 158). By this extension of the insertion areas s5 is unlikely to contribute to this 

 muscle and is, like in Polyphaga, assumed to have been lost, sl+3 seems to be composed 

 of the previous si and s3 since its dorsal insertion includes the areas occupied by si and 

 s3 in Polyphaga and Lamproblatta (si: anterior to the hla-base, compare fig. 157 and 127, 

 185; s3: farther on the right, compare fig. 158 and 133, 188). The dorsal insertion of sl+3 

 reaches with some fibers sclerite L2 in the Ive-pouch; this insertion is typical for s7, which 

 may therefore also contribute to sl+3 (fig.333f). 



The right side has one large primary muscle, s2+4+6, and, in some specimens only, a very 

 small one, s4b. The ventral insertion area of the large muscle includes, in contrast to sl+3 

 on the left side, the lateral anterior margin of the subgenital plate (fig. 147, 333f). Thus, 

 this muscle assumedly contains not only the median s2 and s4 but also the lateral s6. This 

 is also suggested by the fact that the dorsal insertion (fig. 168) extends far into the ventral 

 wall of the genital pouch (compare s6a of Eurycotis, fig. 64). In this latter feature 

 Cryptocercus would be more primitive than Polyphaga and Lamproblatta, whose s6- 

 insertion is restricted to the anterior margin of R3. To what extent each s2 and s4 contribute 



